SceneKit nodes aren't changing position with scene's root node

问题

I'm using SceneKit with ARKit, and right now have a simple app where I tap on the screen and it adds an ARAnchor and a SCNNode to my scene.

At some point, I'm going to want to move the entire scene, so I tried changing sceneView.scene.rootNode.position.x += 10 to test this out. If I call this on any particular node, that node does move appropriately. But calling this on rootNode, nothing happens, where I'd expect every child node (which is every node in the scene) to move along with it.

Why are my other nodes not moving appropriately, and is there something I can do to fix this? Or am I thinking about this wrong?

回答1:

Per the docs for SCNScene.rootNode:

You should not modify the transform property of the root node.

The root node defines the origin of the world coordinate system — all other measurements are relative to it. Hence, it's not meaningful (and is often problematic) to change its position, orientation, scale, or any other aspect of its transform.

If you want to move all the content in your SceneKit scene, create a new node to contain all of the others, and change that node's transform. (You can't do this for nodes added by ARSCNView, because ARKit makes those direct children of the root node, but the whole point of those is positioning them in world space.)

来源：https://stackoverflow.com/questions/44835589/scenekit-nodes-arent-changing-position-with-scenes-root-node